The present invention relates to a film cassette and more particularly to a film cassette which is suitable for receiving a multi-exposure film strip.
The invention also relates to a camera suitable for cooperative use with the film cassette.
Further, the invention relates to a method of making the film cassette.
The most common type of camera are the rollfilm cameras, i.e., still cameras which are available for different types of films, for example, 135-films, 126-films, or 110-cassettes or else roll film on spools. All these cameras have the disadvantage that the sets of spools which carry the unexposed film are relatively large, particularly relatively thick because of the large-diameter film coil which they contain. It is therefore very difficult to carry along a substantial supply of such film, for example on a trip. Moreover, once the film has been exposed, it is not easy to send away, for example, to developing laboratories, and relatively large shipping bags are used which often will not fit into conventional mail slots and are relatively heavy and therefore require additional postage. The same problems are attendant upon a film cassette which has been proposed in German Pat. No. 877,545.
Another proposal has been made in German Published Application No. 2,809,780 which relates to a photographic system in which the light-sensitive film is constructed as a round disc and is accommodated in a flat round cassette in which it is turnable about the center axis of the disc. In this system the cassettes are relatively thin and can be stacked quite readily. However, they are relatively light and therefore a camera which uses this type of cassette must be rather large in relation to the individual picture frame. Moreover, these film discs cannot be developed and copied in the highly expensive developing and copying equipment which is conventionally available in developing laboratories, so that special machinery must be purchased or expensive adapters must be obtained to be able to handle these films.
Another system of film, cassette and camera has been proposed in the magazine "Research Disclosure" December 1978, page 17. In this proposal an elongated film strip is used which is accommodated in a flat elongated cassette of paper which is opaque to light. The cassette paper has a light-tight fold extending over the entire length of the film strip and the cassette can be opened along sequential portions of the fold to permit exposure of a portion of the film, whereupon the fold is subsequently closed again. For this purpose the film together with the paper cassette is transported through the exposure station of the camera, but without the film undergoing any movement relative to its cassette. While this system uses a film cassette which can be readily stacked and which is narrow, the construction of the fold in the cassette which must be light-tightly closed, must be capable of being opened at different locations, and must be capable of being light-tightly reclosed, is relatively complicated. Moreover, cameras for use of such cassettes must necessarily have rather complicated devices for the sequential opening and closing of the paper fold. In addition to the expense involved due to this, there is also the fact that the cameras must be comparatively large because there must be sufficient space available before and after the exposure station to accommodate the equipment for opening the fold and subsequently reclosing it.